This Condition located on the Admin category tab in Search Builder allows you to find records that were created within a specified number of days.
Use Case - How Many New Records
You might want to know how many new records are created each month. Use 30 days and run this every month to get an idea of how many new records are getting added to your database.
Use Case - How Many New Records from Online Registrations
You can also add the Condition Created by User and leave the user ID field empty to find records created during online registrations, which have user ID 0 as the creator.